1. Technical Field
This disclosure relates to an electromechanical switch, more particularly relates to a contact structure for electromechanical switch utilizing a PCB based construction and a moving contact to allow the actuations and have excellent switch performances, such as high isolation and low insertion loss, and the electromechanical switch is capable of transmitting electronic signals ranged from DC to microwave.
2. Description of Related Art
The electronic signal transmission speed is requested growing fast with the technology progress, so that the control switches or relays are required to be capable of processing the 1 GHz or higher frequency signal. The electromechanical switches or relays are for connecting or disconnecting current or circuitry with mechanical design. Conventional contact structure of those electromechanical switches or relays does not consider the problem of high frequency transmission while designing, so that the contact structure is only capable of transmitting DC or extremely low frequency signals. If the present contact structure with mechanical design desires to be added a processing device for high frequency signals, it will meet the problems which are the cost increase in large scale and hard to mass production.
The MEMS switch or relay is used for resolving the problems mentioned above. In brief, it is fabricated on the silicon wafer with semiconductor technology and having the potential of mass production. The micro design is capable of minimizing the volume of the switches or relays. The typical MEMS switch 5, shown as FIGS. 1 and 2, has a pair of electrodes 11 and 14 which are separated by a thin dielectric layer 12 and an air gap or cavity 13 defined by a dielectric standoff 16. The electrode 14 is mounted on a diaphragm or a moving beam capable of mechanical displacement, and the other electrode 11 is jointed on a substrate and cannot move freely. The switch 5 has two states, that is open (shown as FIG. 1) or close (shown as FIG. 2).
The MEMS switch is very small, so that the charged dielectric medium and effects of static friction always interference the stable actuation and release. And the MEMS switch needs low insertion loss and high isolation while transmitting the high frequency electronic signals, so as to define the gap between the electrodes 11 and 14. Therefore, the MEMS switch is restricted while being used for transmitting the high frequency electronic signals.
In addition, the MEMS switch is fabricated with semiconductor technology, and the processes are including repeatedly oxidizing, depositing, transferring, and etching. The processes are complicated and the steps are numerous. If one of the processes is error, the total element must be reworked, so as to make the manufacturing time and cost higher.